高速钢激光表面熔凝层的显微结构SCIEI

本文对W_(18)Cr_4V高速钢进行激光表面熔凝处理,采用光学显微镜和透射电镜分析表明,熔凝层组织为极细的树枝晶。部分枝晶中心保留有δ铁素体。枝晶内为孪晶马氏体和少量位错马氏体,孪晶马氏体上沿孪晶面M_(23)C_6碳化物呈薄片状共格析出。枝晶臂间为富W,V和Cr合金元素的奥氏体和M_6C碳化物。     

我国异型钢管生产分析

分析了我国生产的异型钢管质量水平和品种规格情况,探讨了国产异型钢管的发展方向。     

Poly(N-methylaniline) coatings on stainless steel by electropolymerization

Poly(N-methylaniline) (PNMA) coatings have been electropolymerized on 304 stainless steel alloy by potentiodynamic, galvanostatic and potentiostatic synthesis techniques from aqueous solutions of 0.1 M N-methylaniline (NMA) and 0.3 M oxalic acid. Characterization of PNMA coatings was carried out by cyclic voltammetry, UV-Vis and FTIR spectroscopy techniques. Corrosion behavior of PNMA coated stainless steel electrodes was investigated using linear anodic potentiodynamic polarization, Tafel test, chronoamperometry and electrochemical impedance spectroscopy (EIS) techniques in 0.5 M aqueous HCl solutions. Corrosion test results showed that PNMA coatings possessed protection to uncoated stainless steel against corrosion.     

Corrosion mechanisms of steel concrete moulds in contact with a demoulding agent studied by EIS and XPS

The behaviour of E24 mild steel was studied by XPS analysis and electrochemical impedance spectroscopy (EIS) in a filtered solution of cement (pH 13), and an alkyl N-aminodiphosphonate aqueous solution called Aquadem^® (7?pH?13). XPS results showed that the corrosion products developed in both media consisted of Fe₂O₃, covered by a very thin layer of goethite. The thickness of this oxide layer was estimated to be 3 nm. XPS analysis also demonstrated the adsorption of Aquadem^® on the outer layer of FeOOH for pH lower than the zero charge pH of goethite (7.55). From XPS and EIS results, physical models of the E24 steel/electrolyte interface are proposed as a function of pH. For 11?pH?13, the steel is covered by a passive film, while for pH?10, pitting corrosion takes place. At pH 7, an additional mass transport phenomenon must be taken into account. The fitting procedure provided values for several physical parameters (electrolyte resistance, passive film resistance), from which the film capacitance and the dielectric constant of the oxide layer were calculated.     

我国应重视铁素体及铁素体/奥氏体不锈钢管材的开发

低铬的实用型铁素体不锈钢和低镍的铁素体/奥氏体双相不锈钢是国际上1980年以后迅速发展的两类不锈钢管材新品种。前者以低成本而成为在低腐蚀环境下应用如汽车排气管等的优选管材,后者则以高强度和高耐腐蚀性能的优良组合而成为在含氯离子、H2S等应力腐蚀环境下使用的部件首选材料。介绍了这两类不锈钢(焊)管的研究情况及应用前景,并建议我国应重视和加强对这类不锈钢管材的开发。     

硬质合金与钢的热等静压扩散连接

研究了硬质合金ＹＧ１５Ｃ与４５~＃碳钢的热等静压扩散连接工艺，探讨厂连接温度、压力、保温保压时间、中间夹层及其厚度和连接残余热应力等对接合强度的影响．结果表明：热等静压扩散连接强度强烈依赖于连接温度，受控于连接后因ＹＧ１５Ｃ与４５~＃钢热膨胀失配而产生的残余热应力。采用镍箔作中间夹层可有效地减小残余热应力对连接的影响，显著提高接合强度．     

土壤中SRB及Cl-对1Cr18Ni9Ti不锈钢腐蚀的相互影响

利用交流阻抗测试技术、扫描电镜及表面能谱、失重法、微生物分析等方法 ,研究了在不同Cl-含量的土壤中 ,硫酸盐还原菌对 1Cr18Ni9Ti不锈钢腐蚀的影响规律 .13 6d的试验结果表明 ,不同Cl-含量土壤中SRB菌量在2 3 0 0 0～ 3 5 0 0 0 (个 /克土 )之间 ,Cl-的加入并没有显著影响SRB的生长 ,随着Cl-的加入土壤中SRB的菌量有增大的趋势 ;随着土壤中Cl-含量的增大 ,不锈钢腐蚀电位负偏移 ,而且在接菌土壤中的腐蚀电位比在灭菌土壤中负移幅度更大 ;不锈钢在灭菌土壤中没有发生点蚀现象 ,而在接菌土壤中发生了严重的点蚀 ,最大点蚀深度随着土壤中Cl-含量的增加而增大 ,这说明在土壤中SRB及Cl-的共同作用下 ,增大了不锈钢的点蚀敏感性 .不锈钢在灭菌土壤中的阻抗图谱表现为一个半径很大的容抗弧 ,而在接菌土壤中的阻抗图表现为两个时间常数的双容抗弧     

不锈钢搅拌摩擦焊摩擦头磨损机理研究

搅拌摩擦头技术是搅拌摩擦焊工艺的关键技术.在探讨不锈钢搅拌摩擦焊工艺的基础上,对不锈铜搅拌摩擦焊过程中硬质合金搅拌摩擦头的磨损机理进行了比较系统的试验研究.通过对实验研究结果的分析,初步将搅拌摩擦头的磨损归结为粘结磨损、氧化磨损、扩散磨损、脆性剥落和脆断.     

R102钢低温再热器焊接接头裂纹分析

分析了R102钢低温再热器接头中裂纹特征、裂纹附近金相组织和硬度分布，分析结果表明，接头中裂纹性质为再热裂纹，在高温运行过程中粗晶区有沉淀强化相析出，它们所产生的晶内硬化效果是R102钢产生再热裂纹的重要原因。